Priority queues

In a priority queue a number of values are stored, each with a priority. You can quickly find the values with minimum and maximum priority. Using this data structure you can handle certain things in the order of priority. The following functions exist:

ds_priority_create() Creates a new priority queue. The function returns an integer as an id that must be used in all other functions to access the particular priority queue.
ds_priority_destroy(id) Destroys the priority queue with the given id, freeing the memory used. Don't forget to call this function when you are ready with the structure.
ds_priority_clear(id) Clears the priority queue with the given id, removing all data from it but not destroying it.
ds_priority_copy(id,source) Copies the priority queue source into the priority queue with the given id.
ds_priority_size(id) Returns the number of values stored in the priority queue.
ds_priority_empty(id) Returns whether the priority queue is empty. This is the same as testing whether the size is 0.
ds_priority_add(id,val,prio) Adds the value with the given priority to the priority queue.
ds_priority_change_priority(id,val,prio) Changes the priority of the given value in the priority queue.
ds_priority_find_priority(id,val) Returns the priority of the given value in the priority queue.
ds_priority_delete_value(id,val) Deletes the given value (with its priority) from the priority queue.
ds_priority_delete_min(id) Returns the value with the smallest priority and deletes it from the priority queue.
ds_priority_find_min(id) Returns the value with the smallest priority but does not delete it from the priority queue.
ds_priority_delete_max(id) Returns the value with the largest priority and deletes it from the priority queue.
ds_priority_find_max(id) Returns the value with the largest priority but does not delete it from the priority queue.
ds_priority_write(id) Turns the data structure into a string and returns this string. The string can then be used to e.g. save it to a file. This provides an easy mechanism for saving data structures.
ds_priority_read(id,str) Reads the data structure from the given string (as created by the previous call).